It was the worst thing that had happened to her since that time she died in a car accident after discovering her husband had been cheating on her.

A former star of the soap opera “The Guiding Light” took the witness stand in Manhattan Supreme Court yesterday to testify about some real-life drama — the night she woke up in her bed to see a man climbing in the window.

Ellen Parker, who played Maureen Reardon Bauer on “Light” for seven years, testified that on the night of Aug. 25, 2011, she was wakened by a sound near her second-floor window.

She said she saw the burglar, who “looked startled,” and grabbed for a jewelry box on her dresser.

She later picked the picture of defendant William Pelzer from a photo array.

Pelzer’s lawyer, Kevin Canfield, said “there are no fingerprints or DNA evidence linking him to the break-in.’’